Ventilator



(Model.

B. MERIAM. VENTILATOR. N0. 403,478. Patented May 14, 1889.

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UNITED STATES PATENT OFFICE.

BENJAMIN MERIAM, OF BOSTON, MASSACHUSETTS.

VENTILATOR.

SPECIFICATION forming part of Letters Patent No. 403,478, dated. May 14,1889. Application filed February 1, 1888. Serial No. 262,688. (ModeL) Toall whom it may concern:

Be it known that I, BENJAMIN MERIAM, a citizen of the United States,residing at Boston, in the county of Suffolk and State of Massachusetts,have invented a new and useful Improvement in Ventilators for Buildings,&c., of which the following is a specification.

I attach to the top of a building well or a pipe or a chimney or similarobject a covering, (provided with a glass-armed roof or roof and sideswhen light is to be admitted,) preferably in the shape of a hollow coneor a pyramid, and furnished from its bottom (which is generally at thetop of the roof) to a certain distance upward with walls on the outside,and with, preferably, a double wall also at its top. The top is made soas to curve (with a contour varying according to the requirementspresented) and proceed downward to one side or on all sides a shortdistance, and the bore or hollow of the device being left unclosed atthis bent end the foul air, smoke, &c., drawn from below are dischargedto the external atmosphere. Some minor devices are also added,hereinafter explained, and the object is to provide a simple automaticand constantly-working apparatus for the ventilation of buildings, &c.

In the drawings, Figure 1 is a side view of my device. Fig. 2 is an endView.

In Fig. 1 is seen, in side view, my ventilating device, made preferablyof sheet metal, and supposed to be resting on the roof of a building bymeans of the platform B B, which platform serves for its firm attachmentto the roof. I

O is the upper part of the buildingwell hole, over which the ventilatoris placed. The building-well is a clear passage-way, passing,ordinarily, from the bottom room of a building to and through the roof,the said well being used for ventilation and sometimes for lighting. Thewell in this instance is supposed to be an oblong in horizontal section,but may be round, oval, or square, and the shape of my ventilatorat itsbottom, in horizontal cross-section, is to be made to conform to theshape of the well.

A A, Fig. 1, are the two end walls of the ventilator and proceedperpendicularly upward from the roof. These end walls are sometimesfurnished with windows when extra light is required.

D D Fig. 2, are the two side walls of the device. They are seen in Fig.2 to be inclined diagonally to the level house-roof toward the center ofthe well-space, and on reaching a certain altitude to curve outward andproceed diagonally, respectively, a short distance downward, terminatingat a point a little above the windows E E, Figs. 1 and 2, which areborne, respectively, two by each wallfour in all-by the side walls, D DSometimes only one or two in all, sometimes more than four, windows areused, the number varying according to the size of the well or therequirements as to more or less light. Wheirthe well is not to be usedas a lightconduit, the windows in the ventilator are dispensed with, asalso when, as sometimes happens, my ventilator is placed on the top of achimney or a simple air-passage instead of the ordinary building-well.

F F Fig. 2, (in dashed lines,) are two supplementary side walls of theventilator, placed, respectively, a short distance from the side walls,D D being attached to and running parallel with them, as seen in Fig. 2,a closed chamber, G G being thus formed, respectively, on each side ofthe ventilator.

H H ,Fig. 2, (in dashed lines,) are two windows, (there are two on eachside-four in all,) placed, respectively, in the inner side wallsopposite, respectively, the windowsE E. (The number used of thesewindows varies, of course, with the number of windows placed in theouter side walls, D D.)

J J, Fig. 2, is the ventilator-roof, attached to and supported by theend walls, A A, Fig. 1, and bearing on each side, respectively, twowindows, M M, Fig. 2, M M Fig. 1, (more or fewer, according to the sizeof the ventilator or the requirements as to light, and sometimesdispensed with altogether, like the windows in the side walls, as abovementioned,) there being four windows in allin the roof of theventilator.

K K, Fig. 2, (in dashed lines,) is the inner roof, placed a shortdistance below the roof J J and running nearly parallel with it, and towhich it is attached at each side, as seen in Fig. 2, the outer andinner roofs thus car:

rying between them a closed chamber, L L, Fig. 2. This inner roof bearson each side, respectively, two windows, N N ,Fig. 2, (four in all,)parallel with and opposite to, respectively, the windows M M in the roofJ J. In practice one of these windows of the inner roof is placedbeneath and opposite each of the outer windows in the roof J J P P P P PP P P, Fig. 1, (P P, Fig. 2,) are light-plates, called thetunnel-plates, of sheet metal of appropriate shape, fastened, (in aposition parallel to the end walls, A A2) I respectively, between theupper ends (the parts which proceed downward, respectively) of the sidewalls, D D and the lower ends of the sides of the roof J J. They arecalled the tunnel-plates because they, in conjunction with side wall androof, form a series of tunnels. In this instance they are quadrilateraland angular in horizontal section; but when only one tunnel is used,(say fastened to the top of achimney,) or, say, three or four, (as whenthe building-well is small,) these tunnels are made circular inhorizontal section in their whole length, presenting thus the shape of acone. The size of the ventilator, and hence the number of tunnels, isproportioned to the size of the well.

Operation of the i1wenti0n.--This ventilating apparatus of mine is but asimple mechanical construction of non-moving parts, and depends for itsunvarying and automatic action upon no moving machinery. Its theory,which I have practically and amply tested, rests upon the well-knownscientific fact that air when heated, being surrounded by theatmospheric unchanged air of lower temperature, rises upward, andsubsequently descends on being cooled. My device being duly placed inposition-say as seen in the drawings-it may be supposed that theapartments connected by windows or in any other way with thebui1ding-well,flue, or air-conduit, contain foul air (in the shape ofthe warmed aeriform products of artificial combustion, forinstance) tobe got rid of. There is supposed to be cffected by means of doors,windows, or apertures unobstructed communication between the well andthe room in question. The foul air, being warm, and therefore expanded,weighs less for any given cubic area than the surrounding cold air,which latter presses upon it with superior weight on all sides. Yieldingto this pressure, the warm air passes in the direction of leastresistance, which is upward, and rises in the well. the top of the wellthe heated foul air encounters the sides and top of my ventilator, whichsides and top, being warm, thus do not absorb the heat from the risingair, which thus retains all the heat and expansion imparted to it below.(This is the sole function of the side and roof chambers, G Gr and L L.)At this time and all the time a body of cold air surrounds theventilator above, including its eduction aperture or apertures and thepor- On reaching tions adjacent. This cold air chills the nonjacketedportions of my devicesay from the end of the inverted portion up to thebeginning of the roof and side jackets or the chambers. The result ofthis action is the chilling of the warm air as it reaches the pointreferred to. An increase of its specific gravity, with a contraction ofits volume, occurs simultaneously, and it drops by its own weightdownward through the eduction-aperture and out of the ventilator. Thechilling and dropping of the risen foul air produces invariably andinevitably an imperfect vacuum at and above the eduction-aperture of theventilator, inside the same. The rising body of warmed air rushes tofill this vacuum, is in turn chilled and condensed, drops down and outof the ventilator, and is got rid of, to be followed in endlesssuccession by more warm and foul air. The curving over to a downwarddirection of the top end of the ventilator, it will be seen, verymaterially assists this action, and at the same time prevents thepassage downward of cold air from the surrounding atmosphere, and alsothe dropping of rain, hail, and snow in the ventilator.

The essential features of my invention are, the curved top of theventilator, the contracted top or inverted-tunnel form of the body ofthe ventilator, its tunnel shape from the curve and the side and roofchambers to its end, and the side and roof chambers themselves. Isometimes, however, use simply the curved top and no jacket-made chamberor inner wall to the roof. I sometimes pass horizontal ducts'from eachroof in a buildin g, unbroken, in an upright direction through thebuilding-well to and through the roof, and terminate them, respectively,with a tunnel. The advantage found in practice of the contraction andshaping to a tunnel form of the body of my ventilator is due to the factthat it concentrates the force with which the foul air passes upward,and the same advantage is attained by the use of the tunnel shape of thecurved end. With an inner room, say in the center of a house, or at theend of a close passage-way, and thus unprovided withadequate'ventilation, I sometimes use an' upioo It is-the practice insome cases (as with case the central receiving-room becomes a part ofthe air-duct, and is so considered in the following claim.

I do not claim an air-duct bearing at its top a box with a closed topand a side opening in the form of a downward-curved pipe of the samediameter in all its length; nor do I claim a main air duct or well withits central passage contracted at the top; nor do I claim a box attachedto the main duct, pipe, or well bearing one or more closed chambers atits side or sides. I do not confine myself to any special material forthe roof L L of my Well, but use sheet metal, plate-glass, wood, or anyother convenient substance.

I claim- In ventilators, the combination and arrangement of theventilator herein described,

shown.

BENJAMIN MERIAM. Witnesses:

LEMUEL P. J ENKS, '1. J. HOWE.

